This relates to aliphatic 1-olefin polymerization under conditions designed to give polymer insoluble in the reaction medium.
It has long been known to produce aliphatic 1-olefin polymers utilizing supported chromium-containing catalysts. Later developments in this area have included the production of such polymers under conditions of relatively low temperature so that the polymer produced is largely insoluble in the reaction medium. In such processes the diluent, catalyst and monomer are mixed in a reaction zone and the polymer withdrawn. One particularly suitable technique for carrying out this operation is to utilize a loop reactor with the resulting polymer being withdrawn either continuously or intermittently.
In these various processes there is sometimes encountered severe problems with fouling due to polymer particles building up on the wall of the reaction zone and thus interfering with heat transfer and ultimately causing complete stoppage of the polymerization.
Aluminum alkoxides are known as catalyst adjuvants and have been utilized to effect changes in polymerization characteristics by contacting same with the catalyst prior to introduction of the catalyst into the reactor as disclosed, for instance, in Johnson et al. U.S. Pat. No. 3,642,749.